The Obama administration announced on Wednesday potentially the largest overseas arms sale in US history.

Saudi Arabia has been given the green light to buy up to $60bn of weaponry from key US arms manufacturers.

On the Saudi shopping list is 84 new Boeing F-15 fighter jets, widely used in Iraq and Afghanistan, plus upgrades for the 70 they already own. The F-15 is not the newest fighter out there but the Saudis will get the same specification as recent US sales of similar aircraft to South Korea and Singapore.They're also looking to snap up nearly 200 helicopters, including seventy Apache attack models, used by the US, Israeli and British forces.

Radar and naval contracts may also materialise.

The final price of the deal depends on how many options the Saudis take up over the next two decades.

The US administration has admitted Israel was consulted widely about the sale and, as if to make a point, the Saudis are being denied access to the very latest fighter jet technology - the yet to be completed F-35 Joint Strike Fighter - of which Israel has already bought 20, with options for more.

The state department denies the Saudi deal is all about the threat from Iran.

Andrew Shapiro, the assistant secretary for political-military affairs, was grilled by journalists at Wednesday's daily state department briefing.

Reporter: Let's not beat around the bush, this is about Iran right?

Shapiro: No it’s not!

Reporter: It's not?

Shapiro: It's not solely about Iran, it's about helping the Saudis with their legitimate security needs and they have a number of them

Reporter: Is that one of them?

Shapiro: Sure, they live in a dangerous neighbourhood and we are helping them preserve and protect their security in a dangerous neighbourhood against legitimate security threats.

US authorities are touting the deal as good for jobs. It'll preserve hundreds of thousands of defence related posts at companies like Lockheed Martin, Boeing, United Technologies and Raytheon, just when unemployment remains stubbornly high and with crucial midterm congressional elections just days away.

But critics point to Saudi Arabia's poor human rights record and wonder if this is such a good idea?

Saudi Arabia is frequently cited for infractions by human rights groups. US law denies security assistance to any country with a pattern of such violations.

So now the Congress has thirty days to decide whether or not it should block the deal. If not, defence department procurement lawyers will open negotiations with the Saudis and formal contracts with delivery dates will be drawn up.

John Terrett is a Washington-based correspondent for Al Jazeera English.